Readers here will know that, being a determinist, I'd prefer to dispense with the term "moral responsibility," replacing it with the simple idea of "responsibility." That's because I don't think we have dualistic free will that would allow us to decide between doing "right" and "wrong." If that's the case, then why add the adjective "moral," which implies that one does have a choice?

If we have no free will, we can't choose our acts. If Jerry Coyne has no free will, he didn't choose to write his blog post. Jerry's blog post was determined by natural history and physical laws, not by intelligence.

And, as most of you know, I don't think this omission would overthrow society.

Right. Morality has nothing to do with maintaining the social order.

We'd still put people in prison for bad behavior (but for sequestration, rehabilitation, and as deterrence, but not for retribution), and could also praise them for good behavior -- for praise is an environmental effect that can change someone's behavior or impel others to act well -- but we would be less likely to see people as good or bad by "choice."

The problem with Jerry's plan to suppress bad behavior by sequestration and rehabilitation, rather than by retribution, is that being sequestered and rehabilitated have nothing to do with having actually committed a crime.

You can be sequestered and rehabilitated for all sorts of things, including for the suspicion that you might commit a crime, or because it suits the ends of the people who sequester and rehabilitate. Retribution at least has the virtue that it is a punishment for a crime actually committed.

If there is no moral responsibility, not only is there no guilt. There is no innocence.

And the prison system would be run more humanely, involving studies about the best way to change people's behavior or the best way to deter other people's latent criminality.

Changing behavior and deterring latent criminality don't depend on conviction for an actual crime. Lots of folks behave badly and have criminality latent in them, yet they've committed no crime. Jerry has a (humane) prison cell waiting for them.

What I'd like to ask here, though, is when humans supposedly became morally responsible -- if that's what you believe.

We always hear that "unlike humans, nature is amoral." You can't say that the actions of animals are moral or immoral -- they just are. When a male lion invades another group and kills the cubs, when a chimp tears another chimp to bits, those are just bits of nature, and aren't seen as wrong. And the amorality of nature is touted even by those who realize that our primate relatives show rudiments of morality, making it likely that some of our moral instincts were inherited from our pre-hominin ancestors. So why, when a stepfather kills his stepchild (something that, presumably is not something he decides to do "freely"), that is morally wrong, but when a lion does it, or a chimp kills an infant, it's just nature, Jake.

Jerry's atheism and materialism leave him no way to distinguish behavior in animals from morality in man. This upsets Jerry.

Now the idea of ethics -- a codified set of rules to which we adhere for various reasons, usually as a form of societal glue -- clearly was concomitant with the rise of human society and language. But much of our morality is surely based on evolution.

None of our morality is based on evolution.

I'm not saying that those evolved principles are the right ones to use today: clearly in many cases, as with xenophobia, they aren't. But some of them remain salubrious, including reciprocal altruism, shame, guilt, and so on.